快中子多重性测量技术研究  

Study on Fast Neutron Multiplicity Measurement Technology

作　　者：周志波 李多宏 刘月壮 张少东 张琦[2] 李梦远 金宝亮 张小东 李达 武朝辉 ZHOU Zhibo;LI Duohong;LIU Yuezhuang;ZHANG Shaodong;ZHANG Qi;LI Mengyuan;JIN Baoliang;ZHANG Xiaodong;LI Da;WU Zhaohui(State Nuclear Security Technology Center,Beijing 102401,China;North China Electric Power University,Beijing 100096,China)

机构地区：[1]国家核安保技术中心,北京102401 [2]华北电力大学,北京100096

出　　处：《世界核地质科学》2023年第2期454-461,共8页World Nuclear Geoscience

基　　金：国家国防科技工业局项目资助。

摘　　要：为应对3He短缺情况,采用更加低价、易获取的液闪来探测中子,并推广应用中子多重性技术,研制了一种基于EJ309的液闪快中子探测器,自主开发了中子伽玛甄别电路,采用电荷积分法进行中子伽玛信号甄别,并通过实验验证了该中子探测器在能量阈值为100 keVee(ee—等效能)时,中子伽玛甄别性能参数FOM(Figure of Merit)大于1;在多重性数据分析过程中,为了解决散射中子对多重性符合计数带来的影响,引入散射串扰因子对传统多重性方程进行了修正;为降低测量腔内探测效率的非均匀性对测量结果的影响,通过蒙特卡洛模拟设计了一套球形快中子多重性测量装置,并通过实验验证了其探测效率的均匀性以及测量结果的相对偏差,结果表明:其探测效率的均匀性以及测量结果的相对偏差均好于5%,该工作为快中子多重性测量技术的实际应用奠定了基础。In order to deal with the 3He shortage,low-cost and easy-to-obtain liquid scintillation was used more to detect neutrons,and popularize the neutron multiplicity technology.A liquid scintillator neutron detector based on EJ309 was developed by self-developed neutron gamma discriminator,and the charge integration method was used for the neutron-gamma discrimination.Our experiments verified that the neutron gamma discriminant performance parameter FOM(Figure of Merit)is greater than one when the neutron detector’s energy threshold is 100 keVee(ee represents equivalent energy).In the process of multiplicity data analysis,in order to solve the influence of scattering neutron on multiplicity coincidence count,the traditional multiplicity equation was modified by introducing scattering crosstalk factor.In order to reduce the influence of the nonuniformity of the detection efficiency in the measurement cavity on the measurement results,a set of spherical fast neutron multiplicity measuring device has been designed by Monte Carlo simulation,the uniformity of the detection efficiency and the relative deviation of the measurement results were verified by experiments.The results show that the uniformity of the detection efficiency and the relative deviation of the measurement results are within 5%,our work laid a foundation for the practical application of fast neutron multiplicity measurement technology.

关 键 词：液闪 电荷积分法 中子伽玛信号甄别 散射串扰因子 快中子多重性 

分 类 号：TL8163[核科学技术—核技术及应用] O582[理学—物理] O59